This invention relates to data communications, and more particularly to wireless communication systems, apparatuses and related methods that use adaptively steered antenna arrays.
Computers and other like devices can be interconnected in a variety of ways to allow data to be communicated between them. One of the most common ways to provide such data communication is through a wired network. Wired networks, such as, e.g., wide area networks (WANs) and local area networks (LANs) tend to have a high bandwidth and therefore can be configured to carry digital data at high data rates. One obvious drawback to wired networks is that a user""s movement is constrained since the computer needs to be physically connected to the network. Thus, for example, a user of a portable computer will need to remain near to a wired network junction to stay connected to the wired network.
An alternative to wired networks is a wireless network that is configured to support similar data communications but in a more accommodating manner. Here, the user of a portable device will be free to move around a region that is supported by the wireless network. A well known example of a wireless network is a cellular telephone network. Indeed, in the past, cellular telephone modems have proven popular for use with portable laptop computers and other like devices, despite their relatively low bandwidth.
In the future it is expected that higher bandwidth wireless networks will become more popular, especially in creating metropolitan area networks (MANs) in which users, i.e., subscribers, have the ability to freely move their portable communicating devices around within a coverage area. Many conventional wireless communication systems and networks tend to use omni-directional antennas to transmit and receive data packets, for example, from a router to a subscriber""s device. Being omni-directional, however, such transmissions may interfere with or otherwise restrict the use of other communicating devices that operate in the same frequency band.
Consequently, there is a need for improved packet switched wireless data communication systems, networks and related methods that effectively overcome such potential bottlenecks and other related problems.
In accordance with certain aspects of the present invention, improved packet switched wireless data communication systems, networks, apparatuses, and related methods are provided.
By way of example, the above stated needs and other are met by an apparatus that can be used in a wireless routing network, in accordance with certain implementations of the present invention.
The apparatus includes an adaptive antenna that is configurable to receive a transmission signal from a transmitter and in response transmit corresponding outgoing multi-beam electromagnetic signals exhibiting a plurality of selectively placed transmission peaks and transmission nulls within a far field region of a coverage area. In certain further implementations, the adaptive antenna is also configured to selectively receive at least one incoming electromagnetic signal directed through the coverage area.
The adaptive antenna in certain implementations includes at least one antenna array and logic. The antenna array has a plurality of antenna elements. The logic is operatively coupled to the antenna array and configured to selectively control the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals. When applicable, the logic is also configured to selectively control the reception of the at least one incoming electromagnetic signal.
The above logic can be configured to be responsive to routing information in selectively controlling the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals, and selectively controlling the reception of the at least one incoming electromagnetic signal. In certain implementations, at least a portion of the routing information is dynamically determined and maintained by the logic. By way of example, the routing information may include transmit power level information, transmit data rate information, antenna pointing direction information, weighting information, constraints information, transmission null location information, transmission peak location information, Quality of Service (QoS) information, priority information, data packet lifetime information, frequency information, timing information, and/or keep out area information.
All or part of this routing information may be stored in one or more routing tables. The routing table(s) may further include routing information such as, e.g., IP address information, MAC address information, protocol identifying information, modulation method identifying information, Connection ID (CID) information, node directional information, node transmit power level information, node received signal strength indicator (RSSI) level information, transmit channel information, backup transmit channel information, receive channel information, backup receive channel information, transmission data rate information, receive data rate information, and interference nulling information.
The logic may also maintain weighting values within the routing information. The weighting values are associated with a selected weighting pattern that is to be applied to selectively control the placement of the transmission peaks and transmission nulls within the outgoing multi-beam electromagnetic signals, and further configured to selectively control the reception of the at least one incoming electromagnetic signal. Here, for example, weighting values w(z) may be associated with a polynomial expansion w(z)=w0+w1z+w2z2+w3z3+w4z4+ . . . +wizi. In certain implementations, the weighting values essentially define one or more zeros of the polynomial expansion. These zeros are associated with a direction that a transmission null is selectively placed.
In still further implementations, the logic further includes a search receiver that is configured to determine at least one transmission constraint based at least in part on the received signal. The transmission constraint can be included in the routing information.
The logic may also include a scheduler that is configured to establish at least one traffic schedule based at least in part on the routing information. Here, the routing information can further include transmission demand information. The scheduler can establish one or more traffic schedules by determining at least one assignment for an outgoing data transmission. In certain implementations, the scheduler includes COordinate Rotation DIgital Computer (CORDIC)-based transforming resources that are configurable to be applied to a combined angular, frequency and time arrangement of outgoing electromagnetic signals in establishing the assignment. To help support this and other functions performed in the logic, the routing information may still further include, for example, Quality of Service (QoS) information, subscriber information, queue information, peak data rate information, sustained data rate information, latency information, and/or isochronous performance information. In still other implementations, the routing table may include one or more primitive routines that are configured to support the scheduler.